Select the correct answer. What is this series written in sigma notation?

2.5 + 2.5(1.2) + 2.5(1.2)2 + .

2 + ... + 2.5(1.2)87

ОА.

87

2.5(1.2)*

OB.

2.5(1.2)*1

O c.

2.5(1.2)*

OD.

2.5(1.2)*–1

=1

i think it is everything has to equal 180 so, if i correct 4=c. 6=d. 8=a. 7=b. and the last question would be c. because they are parallel lines and they are congruent.

step-by-step explanation:

the reason everything has to equal to 180 is because that is how it works. i'm guessing that is its rule. 4 and 8 are congruent and parallel so, that would be 30+30 because they have the same number. it would equal 60. 6 and 7 are congruent and parallel so, that would be 30+30 because they have the same number. it would equal 60. 60+60 is 180. so, now you have your answer

the rocket cannot penetrate the ground, in a contextual sense, therefore the roots of this equation should be the domain of this function. i'll let you find the roots of this quadratic equation (hint: use the quadratic formula:  

1- c

2-a

step-by-step explanation:

mark brainliest!

step-by-step explanation: s